getpw(3) Library Functions Manual getpw(3)

getpw - reconstruct password line entry

Standard C library (libc, -lc)

#define _GNU_SOURCE             /* See feature_test_macros(7) */
#include <sys/types.h>
#include <pwd.h>
[[deprecated]] int getpw(uid_t uid, char *buf);

The getpw() function reconstructs the password line entry for the given user ID uid in the buffer buf. The returned buffer contains a line of format


name:passwd:uid:gid:gecos:dir:shell

The passwd structure is defined in <pwd.h> as follows:


struct passwd {

char *pw_name; /* username */
char *pw_passwd; /* user password */
uid_t pw_uid; /* user ID */
gid_t pw_gid; /* group ID */
char *pw_gecos; /* user information */
char *pw_dir; /* home directory */
char *pw_shell; /* shell program */ };

For more information about the fields of this structure, see passwd(5).

The getpw() function returns 0 on success; on error, it returns -1, and errno is set to indicate the error.

If uid is not found in the password database, getpw() returns -1, sets errno to 0, and leaves buf unchanged.

0 or ENOENT
No user corresponding to uid.
buf is NULL.
Insufficient memory to allocate passwd structure.

/etc/passwd
password database file

For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
getpw () Thread safety MT-Safe locale

SVr2.

The getpw() function is dangerous as it may overflow the provided buffer buf. It is obsoleted by getpwuid(3).

endpwent(3), fgetpwent(3), getpwent(3), getpwnam(3), getpwuid(3), putpwent(3), setpwent(3), passwd(5)

2022-12-15 Linux man-pages 6.02